95/05629 A further investigation of the novel multi-stage agitated column for fine coal beneficiation

Abstract

The interaction between sulfide-ion species and smithsonite surfaces and its response to flotation performance were investigated by means of microflotation experiments, surface-adsorption tests, zeta-potential determination, and X-ray photoelectron spectroscopy (XPS) analysis. The microflotation experiments results indicated that addition of Na2S elicited a positive effect on the smithsonite floatability within an appropriate concentration range (<7.5 × 10−4 mol/L), otherwise it showed an obvious negative influence. The surface adsorption tests showed that a significant difference in amounts of sulfide-ion species retained in the pulp solutions was exhibited after smithsonite samples were sulfidized with different concentrations of Na2S. The negativity of the zeta-potential increased with increasing Na2S concentration but decreased under alkaline conditions after adding NaAX. The XPS analysis results revealed that zinc sulfide species formed on the smithsonite surface after sulfidization, and its contents increased with increasing Na2S concentration. Moreover, the sulfidization product formed on the mineral surface was composed of monosulfide and polysulfide, and polysulfide played an important role in the sulfidization flotation of smithsonite. These results demonstrated that excess Na2S concentrations could enhance smithsonite sulfidization but could inhibit the adsorption of collector onto the sulfidized smithsonite surfaces due to the abundant sulfide-ion species retained in the pulp suspension.